[20616] in North American Network Operators' Group
Re: SONET ring questions
daemon@ATHENA.MIT.EDU (Manar Hussain)
Mon Oct 19 11:28:40 1998
Date: Fri, 16 Oct 1998 22:36:15 +0100
To: nanog@merit.edu
From: Manar Hussain <manar@ivision.co.uk>
In-Reply-To: <82k9211gyd.fsf@chimp.juniper.net>
>How many significant digits do you consider acceptable? Even in an ideal
>APS environment, link failure detection and protection switching does take
>finite time. You might get 99.999% uptime, but probably not 99.9999999%.
The thing that always got me was that there never seems to be a mention of
the sampling period for the stat.
>Methinks that you've been subjected to Marketing. ;-)
Well ... I'll give you 99.9999999% on any system you like - with a sampling
period of say every billion years. I think that allows me to stay down for
the first 100 years, long enough to extend beyong the life of any stressed
sysadmin :)
More seriously - SLA's that specify a sampling period then also give an
indication what is considered too long an outage. If you get just under the
.1% downtime allowed per year all in one go you may well be pretty pissed
at being told the 8 hour outage was within the SLA.
Manar
